Statics Forces Problem (Trusses)

I was doing a problem with my friend (the image that is attached to this) and when looking up a solution online... It said that the forces at reaction supports B and C are 5 kN in the y direction...

2. Relevant equations

3. The attempt at a solution

We thought that since these members are trusses, all the force from the external loading... is 15 (10 + 5) and that the reaction supports in the y direction at B and C should be 7.5. Where did we go wrong?

I was doing a problem with my friend (the image that is attached to this) and when looking up a solution online... It said that the forces at reaction supports B and C are 5 kN in the y direction...

2. Relevant equations

3. The attempt at a solution

We thought that since these members are trusses, all the force from the external loading... is 15 (10 + 5) and that the reaction supports in the y direction at B and C should be 7.5. Where did we go wrong?